Lens-grinding machinery



July 16, 1929. A. E. MAYNARD LENS GRINDING MACHINERY Filed March 25,1925 2 Sheets-Sheet l July 16, 1929. A. E. MAYNARD I LENQ GRINDINGMACHINERY Filed March 23. 1925 2 Sheets-Sheet 2 INVENTOR Illa al e mnerd Patented July 16, 1929.

ALBERT n. MAYNARD, or soU'rHB IDeE, mnssaonnsnrrs, nssreno 'rro AMERICANOPTICAL COMPANY, or SOUTHBRIDGE, MASSACHUSETTS, A VOLUNTARY AssooIA TIONor MASSACHUSETTS.

, LENS-GRINDING MACHINERY.

Application filed March 23, 1925. Serial No. 17,546.

This invention relates to improvements in lens grinding machinery, andhas particular reference to lens edge grinding machinery and lensclamping means therefor.

An important object of the present invengreat degree of'accuracy andmaintained so in relation to its center of rotation.

till another object is to provide a lens edging machine having animproved and sim plified work supporting carriage.

A further object is to provide improved means for positioning a lens inproper central and axial alignment with its rotating mechanism. 1

Another object is to provide such a device which will be simple inconstruction, strong and durable in service, efficient in use, and anadvance in the art. 7

With these and other objects in view, the invention resides in the noveldetails of construction, combination and arrangement of partshereinafter more fully set forth, illustrated. in the accompanyingdrawings, and specifically pointed out in the appended claim. 1

In the drawings, wherein similar reference characters designatecorresponding part throughout the several views:

Figure l'is a front elevation of a lens edge grinding machine embodyingthe invention;

Figure 2 is a fragmentary end elevation thereof;

Figure 3 is a vertical longitudinal sectiona1 view through thedetachable lens clamping mechanism i 7 Figure 4 is a similar viewshowing the clamp opened; v

Figure 5 is a front elevation of a modified form of lens holding memberFigure 6 is a detail perspective view of the lens driving bushing; and

Figure 7 is a cross section on line 7-7 of Figure 2.

In Figure 1 is illustrated a conventional lens edge grinding machine,which comprises a base member 10, on which is'r'otatably mounted anabrasive wheel 11 adapted to be rotated through the instrumentality of adrivmg pulley 12. Preferably disposed-at the front of the base member 10is a worksupporting carriage 13, which is pivotally mounted upon theshaft 14, and carries in its upper free end a lens driving shaft-orspindle 15. The shaft 14 isadapted to be rotated by means of a train ofgears 16 which are preferably connected to the main grind stoneShaft,.65 whereby to be synchronously rotated by the pulley 12. Thepower thus imparted to the shaft 14 is transmitted-to the lens spindle15v through the gears 17 It is to be understood that this invention in 70 its broadest aspect comprises the provision of a detachable lensholder on any lens edging machine, so that I do not limit myself to theprecise structure of machine illustrated in the drawings, since thereare a number of machines well known to those skilled in the art to whichmy deviceis readily adaptable. Referring now to Figures 3 and 4, it willbe seen that my'improved lens holder comprises a pair of supporting arms18 and 19 held in relatively adjustable position, as by the pivotalconnection 20. Adjacent their upper ends the supporting arms 18 and 19are provided with suitable bosses 21 and 22, which are normally in axialalignment, and which are adapted to form bearings for the rotat-- ableclamping members. r In the boss 21 is mounted a sleeve 23 which carrieson its inner extremity a suitable lens clamping cushion or pad 24 of anyordinary or preferred type. If desired the devicemay be provided withanti-friction bearings and be held against relative longitudinalmovement by means of a collar 26. The outer extremity of the sleeve. 23is preferably notched for the reception of a driving key 27,

V which is carried by a sleeve 28 mounted upon the lens spindle 15.Furthermore, the extremity of the sleeve 23 is threaded as at 29 forengagement by a locking nut 30, whereby the device may be securelyattached to the spindle 15. From this it will be evident that when thedevice is connected to the lens holding carriage of an edging machine,the sleeve 23 will be rotated by the spindle 15 and, of course, the lensclamping pad 24 will be similarly rotated.

Disposed in the boss 22 of the supporting the direction of the clampingpad 24. A

suitable bushing 36 is fastened to the end of the shaft 31 to hold theclamp member 32 in the boss 22 in its operative position retaining theballbearings 25 and the spring 35 in their respective operativepositions in the boss 22.

Adjacent the opposite end of the supporting arm 19 is a pivoting pin 37upon which is pivotally mounted a locking cam 38 operative by means ofthe handle 39. The operative face of'the cam 38 is adapted to engage theinner surface of the supporting arm 18,

whereby to maintain the two supporting arms 18 and 19 in parallelrelationship so that the opposed lens clamping members will be in properaxial alignment.

By referring particularly to Figure 4 it willbe seen that when thehandle member 39 is moved upwardly so as to disengage the cam 38 thearms 18 and 19 will move about the pivot 20 so as to separate theclamping pads 24 and 33. v

A spring actuated catch member 40 is car ried, preferably on the frontside of the carriage 13, and adapted to hook over one of the supportingarms, as clearly shown in Figure -1, whereby the whole detachable memberwill be securely held in operative position on the machine.

In use a lens A to be ground is marked in the usual manner well known tothose skilled in the art, whereby to properly relate the axis ofrotation with the optical center of the lens, and thereafter it maybeinserted in the detached lens holder. It is especially to be notedthat in view of the fact that the lens holder is detachable, the lensmay be very accurately aligned and immediately clamped and'securelyheld. In view of the fact that the shaft 31 and associated parts 32 and33 are yieldingly mounted in the boss 22. the device is capable ofengaging lenses of different thicknesses, which is a very necessaryqualification. fter the lens has thus been clamped the device is appliedto the carriage 13 of the machine by connecting the sleeve 23 to theshaft 15 and securely locking the nut 30. Power may then be applied torotate the grindstone 11 and the lens A simultaneously, as is well knownin the art.

, In Figure 5 is illustrated a modified form of lens holder. Thiscomprises a pair of relatively adjustable supporting arms 41 and 42, oneof which carries a pair of guide pins 43, upon which the other arm isslidably mounted as; at 44. Disposed between the members 41 and 42 andencircling the guide pins 43, are a pair of compression springs 45,

which tend to normally force the two supporting arms away from eachother. A locking cam 46 is mounted on the member 41 and operativeagainstthe outer face of the supportingarm 42, whereby when its handle 47 isdepressed it will force the supporting arms and their associated lensclamps towards each other and into operative relationship, as clearlyshown by dotted lines in Figure 5. The application of this modificationto the carriage of the grinding machine is'just the same as in thepreviously described embodiment. I

From the foregoing it'will be evident that I have provided a novel lensclamping mechanism for edge grinding machines, which in View of itssimplicityand ease of operation will be an improvement in the art.Obviously changes may be resorted to in the minor details ofconstruction and proportion of parts, and the right is herein reservedto make such changes falling within the scope of the spirit of theinvention.

Having thus described my invention, I claim: 1 v y In a device of thecharacter described, a supporting arm having a boss with a bore forabearing, the axis of the bore being substanapnended claim withoutdeparting from the tially normal to the support, a lens clamp bearingslidably and rotatably mounted in the bore and having a resilient lenscontacting face, means for holding the bearing in the bore and limitingits sliding movement therein, resilient means in the bore engaging thebearing and tending to urge the bearing in lens engaging direction, asecond support separated from and substantially, parallel with the firstsupport and having a boss with a bore, the axis of which is aligned withthe axis of the first bore when the supports are in lens engagingposition, a lens-clamp bearing in the second bore rotatably'mountedtherein and having a resilient lens contact face and havinginterengaging means by which it may be engaged with the drive shaftof alens edging machine, means for holding said bearing in its bore, meansconnecting the two supports whereby the distance between them at thelens engaging position may be changed, and means for locking the twosupports in the lens engaging position.

ALBERT E. MAYNARD.

